Oki c321dn problem printing on number plate reflective

Good Morning- I am a Regional Sales Manager for OKI in the US for the Colorpainter Wide Format printers, so if something like this comes up, we have to send it through the dealer technicians before our in-house techs get involved. Have you been able to do that yet, or are you hoping to get an answer from the forum this weekend before reaching out to them Monday?

I don't know much about that product, but it appears that its a toner based printer. I have a few obvious questions, so please understand that I'm just trying to eliminate a few things... Did this suddenly start, or was it a progressive issue? Is the toner cartridge full/new? Have you tried a new toner cartridge? Has there been any change to the media that you're printing on recently? Have you tried wiping off the media with a light solvent (70% isopropyl alcohol) to get an residue that may be on there?

I am stabbing in the dark with those questions, I realize, but hoping to help you. Also, how old is the printer? Could it be a defective "toner heating unit" or what ever is used to bond the toner to the media?

Best of luck to you.